Abnormal motor condition indicator



June 5, 3945. P. H. MORSE 2,377,569

ABNORMAL MOTOR CONDITION INDICATOR Filed Dec. 26, 1941 PaaZJZManve INVEN TOR.

Patented June 5, 1945 UNITED STATES PATENT OFFICE- ABNORMAL MOTOR CONDITION INDICATOR Paul H. Morse, Santa Barbara, Calif. Application December 26, 1941, Serial No. 424,547

1 Claim. (Cl. 177-311) This invention relates to an automatically controlled means for use in connection with motor vehicles or aeroplanes of, instantly and regardless of cause, determining certain abnormal conditions of the engine such as failure of the oil pump to deliver suflicient pressure; failure of the electrical generator to function; or failure of the cooling system to maintain the temperature below the danger point; and giving warning thereof to the operator.

An important object of the invention is to provide a pressure-operated switch, controlled by engine oil pressure and sensitive to changes in oil pressure, to complete a circuit to a device capable of producing an audible signal when the pressure falls below a certain minimum.

Another object of the invention is to provide an electrically-operated switch, controlled by changes in the generator voltage, to complete a circuit which includes a device capable of producing an audible signal when this generator voltage falls below a certain minimum.

Another object of the invention is to provide electrical circuits to combine the above-mentioned switches and signal unit in such a way that only the proper functioning of both the oil pumpand the generator can prevent the warning signal from being. sounded.

Another object of the invention is to provide a switch, operated by the vacuum of the engine inlet manifold, for the purpose of insuring the sounding of the signal in the event that both the oil pump and the generator fail to function at the same time.

With the foregoing and other objects in view which will appear as the description proceeds, the invention consists of certain novel details of construction and combinations of parts hereinafter more fully described and pointed out in the claim, it being understood that changes may be made in the construction and arrangement of parts without departing from the spirit of the invention as claimed.

Referring to the drawing:

Figure 1 is a diagram indicating the switches and circuits of the system together with the si nal unit,

Figure 2 is a view illustrating one of the tube type switches used in the system.

Referring to the drawing in detail, the reference character 9 designates the battery of the I vehicle which is grounded to the chassis at I ll.

Leading from the battery 3 is a wire II which is connected to wire l2 through the ignition switch 3.

The reference character I 5 designates the armature of the relay which is provided with a contact member H5 at its free end, this contact member It being designed to close with either contact member I! or contact member l8. When the engine is not running and the relay not actuated by the generator, contact I6 is held closed with contact I! by the action of the coiled spring IS.

The reference character 25 is an oil pressure operated switch the contact member 24 of which is adapted to move between contact member 2| and contact member 22; being held closed with contact 2| by the spring action of the :arm of switch member 25 when the engine oil pressure is below a certain minimum. Switch member 25 together with its contact 24 is grounded at 21.

The reference character 3| is a switch operated by the inlet manifold vacuum of the engine. When there is no manifold vacuum, contact member 28 and contact member 30 of the switch are held open by the spring action of the tube on which contact is carried. At all times when the engine is running vacuum keeps contacts 28 and 3H closed. Switch 3| together with its contact 30 is grounded at33.

The reference character 34 is a heat operated switch mounted on the engine cylinder head or block. Contact member 35 and contact member 36 are normally held open by the spring action of the bimetal arm on Which contact 35 is carried. When the bimetal strip is heated it bends and in so doing closes contacts 35 and 36 above a certain temperature. Switch 34 together with its contact 35 is grounded at 39.

The different units described in the foregoing are connected electrically as follows: buzzer 5 is connected to contact l6 of relay 6 by wire 38; contact l8 of relay 6 is connected to contact 2| of oil pressure switch 25 by wire 20; contact I! of relay 6 is connected to contact 22 of oil pressure switch 25 by wire 23; contact 28 of vacuum switch 3 l is connected to contact 22 of oil pressure switch 25 (or to wire 23) by wire 29; and contact 36 of heat operated switch 34 is connected to buzzer 5 by wires 31 and 38.

The operation of the device is as follows:

When the ignition switch has been turned on but the engine not yet started the buzzer is silent because its circuit is open between contacts l6 and i8; between contacts 22 and 24; and between contacts 28 and 30.

When the engine is started and the generator is in good order the voltage of the latter builds up quickly and causes relay armature l5 to close contacts I6 and I8, and to open contacts l6 and I1. At the same time the oil pressure rising to normal causes switch arm 25 to close contacts 22 and 24, and to open contacts 2| and 24. Therefore the buzzer. its circuit being open between contacts l6 and I1 and between contacts 2| and 24, remains silent.

However, if then the generator should fail to function contacts 16 and I! close, completing the buzzer circuit through to closed contacts 22 and 24 of the oil pressure switch and on to ground: and causing the warning signal to be sounded.

If instead, the oil pressure should fail, contacts 2| and 24 close, and the buzzer circuit is completed through closed contacts l6 and i8 of the relay; through contacts 2| and 24; and on to ground. The warning signal then is sounded.

If both the generator and oil pump should fail to function at the same time, the buzzer circuit is completed through closed contacts l6 and II of the relay; through closed contacts 28 and 30 of the vacuum switch: and on to ground. The

point, contacts 35 and 36 of the heat .operated switch close completing the buzzer circuit through to ground; and causing the warning signal to be sounded.

What I claim is:

A signaling system for indicating failure of oil pressure in the lubricating system of an internal combustion engine, the failure of a generator driven by the engine to generate or the failure of both comprising an electrically operated signal, a relay, a circuit including the winding of the relay and the generator, said relayhaving a front contact engaged by a movable contact of the relay when the relay winding is energized and a back contact engaged by the movable contact when the relay is deenergized, a device responsive to pressure of the oil in the lubricating system having a front contact engageable by a movable contact of the device when the pressure is normal and a back contact which is engageable by the device movable contact when the pressure fails, a first circuit for the signal including in series a source of energy independent of said generator, the movable relay contact and its front contact and the movable device contact and its back contact, a second circuit for the signal including said source, the movable con'- tact of the relay and its back contact and the movable contact of the device and its front contact, and a third circuit for said signal including said source, the movable contact and the back contact of the relay the front contact of the device and a switch closed in response to vacuum in the engine manifold.

PAUL H. MORSE. 

